:root {
  --bg-color: #f8f9fa;
  --text-color: #212529;
  --primary-color: #0d6efd;
  --secondary-color: #6c757d;
  --card-bg: #ffffff;
  --success-color: #198754;
  --danger-color: #dc3545;
  --border-radius: 12px;
  --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: #121212;
    --text-color: #e0e0e0;
    --card-bg: #1e1e1e;
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
  }
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
}

/* Navbar */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background-color: var(--card-bg);
  box-shadow: var(--box-shadow);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.navbar-brand {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-color);
  text-decoration: none;
  letter-spacing: -0.5px;
}

.nav-links a {
  margin-left: 1.5rem;
  text-decoration: none;
  color: var(--secondary-color);
  font-weight: 500;
  transition: var(--transition);
}

.nav-links a:hover, .nav-links a.active {
  color: var(--primary-color);
}

/* Container */
.container {
  max-width: 1600px;
  margin: 0 auto;
  padding: 2rem;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.5rem 1.5rem;
  border-radius: var(--border-radius);
  border: none;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  font-size: 1rem;
}

.btn-primary {
  background-color: var(--primary-color);
  color: white;
}
.btn-primary:hover {
  background-color: #0b5ed7;
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(13, 110, 253, 0.3);
}

.btn-success { background-color: var(--success-color); color: white; }
.btn-danger { background-color: var(--danger-color); color: white; }

/* Waterfall Flex Masonry */
.gallery {
  display: flex;
  gap: 1.5rem;
  align-items: flex-start;
}

.gallery-column {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.gallery-item {
  margin-bottom: 0px;
  border-radius: var(--border-radius);
  overflow: hidden;
  background-color: var(--card-bg);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
  position: relative;
  opacity: 0;
  animation: fadeIn 0.5s forwards ease-in-out;
}

@keyframes fadeIn {
  to { opacity: 1; }
}

.gallery-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 15px rgba(0, 0, 0, 0.1);
}

.gallery-item img {
  width: 100%;
  max-height: 80vh; /* Prevent extremely long images from breaking the flow */
  display: block;
  object-fit: cover;
  transition: var(--transition);
}

.gallery-item:hover img {
  transform: scale(1.02);
}

/* Loading Spinner */
.loading {
  text-align: center;
  padding: 2rem;
  color: var(--secondary-color);
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid rgba(0,0,0,0.1);
  border-left-color: var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Upload Area */
.upload-container {
  background-color: var(--card-bg);
  border-radius: var(--border-radius);
  padding: 3rem;
  text-align: center;
  box-shadow: var(--box-shadow);
  max-width: 600px;
  margin: 2rem auto;
}

.drop-zone {
  border: 2px dashed var(--secondary-color);
  border-radius: var(--border-radius);
  padding: 3rem 2rem;
  cursor: pointer;
  transition: var(--transition);
  margin-bottom: 1.5rem;
}

.drop-zone.dragover {
  border-color: var(--primary-color);
  background-color: rgba(13, 110, 253, 0.05);
}

.drop-zone p {
  color: var(--secondary-color);
  margin-top: 1rem;
}

#fileInput {
  display: none;
}

/* Upload Results List */
.upload-results {
  margin-top: 2rem;
  text-align: left;
}

.result-item {
  padding: 1rem;
  border-radius: var(--border-radius);
  margin-bottom: 0.5rem;
  background-color: var(--bg-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-left: 4px solid transparent;
}

.result-item.success { border-left-color: var(--success-color); }
.result-item.duplicate, .result-item.similar, .result-item.limit { border-left-color: #ffc107; }
.result-item.error { border-left-color: var(--danger-color); }

/* Admin Grid */
.admin-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.5rem;
}

/* Upload Page Layout */
.upload-page-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: start;
}

.upload-container h2, 
.upload-results-container h3 {
  margin-top: 0;
}

@media (max-width: 992px) {
  .upload-page-grid {
    grid-template-columns: 1fr;
  }
}

.upload-results-container {
  background: var(--card-bg);
  padding: 2rem;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  max-height: 600px;
  overflow-y: auto;
}

.admin-card {
  background-color: var(--card-bg);
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--box-shadow);
}

.admin-card img {
  width: 100%;
  height: 200px;
  object-fit: contain;
  background-color: #000;
}

.admin-card-body {
  padding: 1rem;
}

.admin-meta {
  font-size: 0.85rem;
  color: var(--secondary-color);
  margin-bottom: 1rem;
  word-break: break-all;
}

.admin-actions {
  display: flex;
  gap: 0.5rem;
}

.admin-actions button {
  flex: 1;
}

/* Toast Notification */
.toast-container {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 9999;
}

.toast {
  background-color: var(--card-bg);
  color: var(--text-color);
  padding: 1rem 1.5rem;
  border-radius: var(--border-radius);
  box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  margin-top: 10px;
  transform: translateX(120%);
  animation: slideInright 0.3s forwards ease-out;
  display: flex;
  align-items: center;
  gap: 10px;
  border-left: 4px solid var(--primary-color);
}

.toast.success { border-left-color: var(--success-color); }
.toast.error { border-left-color: var(--danger-color); }

@keyframes slideInright {
  to { transform: translateX(0); }
}

.modal {
  display: none;
  position: fixed;
  z-index: 2000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-color: rgba(0, 0, 0, 0.92);
  backdrop-filter: blur(5px);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.modal.show {
  display: flex;
  opacity: 1;
  flex-direction: column;
}

.modal-content-wrapper {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 40px 20px 80px; /* leave space for controls at bottom */
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,0.3) transparent;
}

.modal-content-wrapper::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

.modal-content-wrapper::-webkit-scrollbar-thumb {
  background: rgba(255,255,255,0.3);
  border-radius: 3px;
}

.modal-content {
  max-width: 90vw;
  display: block;
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
  transform-origin: top center;
  transition: transform 0.2s ease;
  cursor: zoom-in;
  margin: auto;
  user-select: none;
  -webkit-user-drag: none;
}

.modal-close {
  position: fixed;
  top: 15px;
  right: 25px;
  color: white;
  font-size: 36px;
  font-weight: bold;
  cursor: pointer;
  transition: color 0.3s ease;
  z-index: 2001;
  text-shadow: 0 2px 6px rgba(0,0,0,0.5);
}

.modal-close:hover,
.modal-close:focus {
  color: #bbb;
}

.modal-actions {
  position: fixed;
  bottom: 20px;
  left: 20px;
  display: flex;
  gap: 15px;
  z-index: 2001;
}

.modal-controls {
  position: fixed;
  bottom: 20px;
  right: 20px;
  display: flex;
  gap: 8px;
  align-items: center;
  z-index: 2001;
}

.btn-icon {
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 1.3rem;
  cursor: pointer;
  transition: all 0.2s;
  backdrop-filter: blur(4px);
}

.btn-icon:hover {
  background: rgba(255, 255, 255, 0.35);
  transform: scale(1.1);
}

.gallery-item {
  cursor: zoom-in;
}